Search PubMed⌕ Search

Biomedical subjects

J M Cooper

Publications and source records attributed to J M Cooper.

At least 181 records · Page 10Linked to original sources
PubMed1974

Stimulation of erythroblast maturation in vitro by sphingolipids.

A lipid factor previously isolated from leukocytes and found to stimulate basophilic erythroblast formation in an in vitro system of incubated rabbit bone marrow cells has been analyzed by thin-layer chromatography, gas-liquid chromatography, and gas-liquid chromatography-mass spectrometry. The biologically active components are sphingosine ceramides of tetracosanoic and dehydrotetracosanoic acids. Tests of a series of related ceramides show a high degree of structural specificity for the C(24)-V-acyl compounds with significant but markedly lower activity of the C(22) analog. Commercially available sphingomyelin shows activity comparable to that of the tetracosanoic acid ceramide. Sphingosine and tetracosanic acid supplied in equimolar amounts have negligible activity. The results, in the context of other findings, suggest a possible supportive role of plasma ceramides and sphingomyelins in red cell maturation.

Animals↗
PubMedDate not supplied

Portal vein velocities measured by ultrasound: usefulness for evaluating shunt functioning following TIPS placement and TIPS revision.

BACKGROUND: To assess the usefulness of following portal vein velocities by Doppler ultrasound in evaluating shunt functioning after transhepatic intrajugular portosystemic shunt (TIPS) placement and revision. METHODS: We retrospectively analyzed 39 patients who underwent a TIPS procedure in the preceding 4 years. Portal vein (PV) velocities were measured by Doppler ultrasound before and after TIPS insertion and revision and were correlated with portosystemic gradients (PSG) measured at angiography. RESULTS: Mean PV velocities increased from 18 +/- 6 cm/s before TIPS placement to 50 +/- 21 cm/s (p < 0.001) after TIPS placement, with corresponding decrease of mean PSG from 20 +/- 6 to 8 +/- 3 mmHg (p < 0.001). Mean PV velocities significantly increased from 24 +/- 6 to 43 +/- 14 cm/s after TIPS revision (p < 0.02), with decrease of PSG from 17 +/- 6 to 9 +/- 5 mmHg (p < 0.05). A significant correlation was found between all PV velocities and their corresponding PSG (Spearman r < 0.61, p < 0.001). CONCLUSION: PV velocities significantly correlate with changes in PSG. Following portal vein velocities by ultrasound is useful for early evaluation of shunt functioning following TIPS.

Angiography↗